James Randi, Global Warming and the Nature of Scepticism

James Randi is a hero to many rational people around the world. He has done more than, perhaps, any person alive to promote rational and clear thinking about claims of the paranormal and alternative medicine. His million dollar challenge acts as a marvelous foil to mountebanks and charlatans. He simply says to them, “demonstrate what you claim, under controlled conditions, and the prize is yours.” This of course, leaves the proud boasters with nothing to do but attempt the futile, or resort to bluster and anger. Which makes them look deservedly silly.

It was something of a shock then to see Randi write an article on his site that questioned the scientific consensus that man made activities are responsible for climate change and that dramatic intervention is required. Such views, we tend to think, are the preserve of the ‘denialist’, loon or vested interest. How could Randi do such thing?

Firstly, of course it is perfectly respectable to cast a skeptical eye over the apparent consensus of global warming. There are indeed undoubtedly inflated claims around, and we need to be on our guard. The activities of lobby groups, such as Greenpeace, have done much to damage the scientific credibility of the green agenda over the years. However, the science community has acted independently of these groups and the consensus has emerged from within rather than channeled and gilded by the usual environmental loud mouths.

However, it was not that Randi questioned the science so much, as that his article was full of so many quite obvious logical fallacies. The Master of Spotting a Phony Argument from a Hundred Paces appeared to fall for his own flawed rhetoric. He appeared to use, astonishingly, arguments from personal incredulity, and arguments from popularity. But, we must not be too harsh here, for there are very important differences between the style of Randi’s arguments and those of the more foaming end of the climate discussion. We see plenty of places in his argument where he lays forward his own lack of knowledge, low expertise and his undoubted capacity to be wrong. I do not believe for a moment that his mind is made up and that he is quite capable of receiving arguments that would show him he had “erred in coming to a certain conclusion”.

But this does leave us with a rather interesting question. How can we, as non experts, but sceptics, come to sound beliefs about areas where we do not have the training, experience and qualifications? Must we remain silent outside of our own fields, or are there reliable ways of coming to good conclusions? This is not an academic exercise as it is precisely what we are asking our politicians to do if we want them to act over issues like global warming.

Looking at Randi’s arguments, he appears to place significant weight on the fact that a group, the Petition Project, has created an online petition that has attracted “some 32,000 scientists, 9,000 of them PhDs” attacking the consensus position. Against this he weighs his distrust of academics who “are strongly influenced by the need to be accepted, to kowtow to peer opinion, and to “belong” in the scientific community.” Randi has previously made his contempt clear about many academics – and it is quite understandable. His exposing of Uri Geller was in the face of people with PhDs who had concluded he was for real. He was used by John Maddox of Nature to investigate the spurious homeopathic experiments of academic Jacques Benveniste. Indeed, as Ben Goldacre has so succinctly put it as his first law of bullshit dynamics: “There is no imaginable proposition so absurd that you cannot find at least one person, somewhere in the world, with a PhD or professional post, who is happy to endorse it.” His distrust of the academic is deep – and rightly so.

But that, of course, does not mean that all academics cannot be trusted and that all expertise is flawed. As Ben Goldacre might say, having a PhD is just a risk factor for being correct. Randi is faced with two camps, both who appear to contain plenty of academics. How do we decide who is the most credible?

The philosopher Bertand Russell wrote a very famous essay, On the Value of Scepticism, on just this problem. Russell too was concerned about how we should evaluate the opinion of experts when we have no direct understanding of their field. His basic ‘radical’ idea was that “that it is undesirable to believe a proposition when there is no ground whatever for supposing it true”. But he saw the problem was that we must on many occasions bow to the opinions of experts. How can we do that without falling foul of an appeal to authority – a basic no-no of any good sceptic?

He came up with the following rules of thumb:

The scepticism that I advocate amounts only to this:

(1) that when the experts are agreed, the opposite opinion cannot be held to be certain;

(2) that when they are not agreed, no opinion can be regarded as certain by a non-expert; and

(3) that when they all hold that no sufficient grounds for a positive opinion exist, the ordinary man would do well to suspend his judgment.

These propositions may seem mild, yet, if accepted, they would absolutely revolutionize human life.

The problem of who to believe has now shifted to one of how to recognise true expertise and how to understand the degree of unanimity between them. Perhaps, Randi’s mistake was to ignore the obvious expertise of climate scientists and to weigh too heavily the inferred ‘expertise’ of a group of ‘scientists’ some of whom just happened to have PhDs (in what, we do not know.)

For me, as a non climate scientist, I have to recognise that condition (1) appears to all intents and purposes to be fulfilled on the issue of climate change. When I hear people challenging the consensus, it is almost invariably from people who cannot truly be counted as experts. We are left with a few mavericks outside of the consensus and they do not look like enough to challenge position (1) to me.

Now, as with all rules of thumb, this does not mean that the experts are right. We still have to guarded and watch the scientific process as it gathers new data. It is quite possible for a consensus to be wrong. As sceptics, we must not drop our guard. But for now, it does indeed look as if we must accept that global warming is real and that we must act, given the very strong unanimity of experts in this field. Russell’s rules would compel us to accept that the challengers of the climate consensus cannot be treated as if they are right and that we should proceed (with due sceptical caution) with the experts.

And as sceptics, we must treat Russell’s rules with the full application of thought. Scepticism does not lend itself too well to rules of thumb as it is the exceptions that can catch us out. Should I accept the total consensus of homeopathic experts that their sugar pills are an amazing panacea? No of course not. I must think about what it means to be a ‘homeopathic expert’. Do these experts have coherent and consilient theory of what is happening? No. Do these experts have a reproducible and rigorous data set that shows a homeopathic effect? No. Homeopaths are pseudo-experts with few of the attributes of genuine experts. They lack academic credibility and look more like a group of similarly deluded individuals whose arguments cannot withstand a moment’s scrutiny.

For me, evaluating the claims of homeopaths, chiropractors and the like is useful because it provides a sandpit where we can learn how to spot flawed reasoning and faulty logic without getting too hurt. These skills are valuable in all walks of life; scientific, political and personal. But we must recognize that our sceptical ninja skills are most honed in our domains of comfort. As we step out of those zones, we have to be doubly on our guard that we are not succumbing to the same logical fallacies that we are so usually critical of.

can anyone think of a case where the vast overwhelming majority of scientists, in their own field, all around the world, for a long period of time, by virtue of conspiracy (since that is the commonest accusation) or foolishness, held an opinion that was demonstrably wrong with reference to the facts available the time? and unanimously refused to concede to good quality arguments against their position? i'd be interested if there were any.

If you took a loose definition of 'scientist' I suppose you could reasonably argue that, for instance the teachings of someone like Claudius Galen were more or less engraved in stone until around the mid 1500's – even though the facts contradicted them.

"His influence was so great that even when public readings from his texts were contradicted by the plain evidence of simultaneous dissections of the body, these discrepancies were ignored" – Medical Blunders, Robert Youngson & Ian Schott

However, I'd argue that this case and others like it from the same time can reasonably be ignored, as they can safely be considered pre-scientific. I can't think of any case like that from the last hundred or so years. I'm definitely not an expert here, and I could easily be wrong, but that's my current view.

Ben Goldacre: Many people claim this was (and to some extent is currently) the case for generative grammar in linguistics, providing you treat that as a science. It's far from (obviously) demonstratably incorrect though, and though it's less popular these days many people still support and work in the paradigm, myself included.

Re-reading Randi's comments, I strongly suspect this first post is a decoy. Exactly because he uses the same rhetorics as you would find with usual arguments defending quackery or other 'denialisms'. For example, he specifically states that of the 32,000 scientists who signed the petition 9,000 are PhDs. Which means, 21,000 aren't even PhDs, no matter what subject or qualified to speak on the subject. So what is their scientific background? Since the JREF announced a follow-up comment soon, I expect a proper debunking of the first post. After all, this is the Season of Reason…

If you think of decisions and opinions as taking a bet on the best alternative, you would want to bet on the option with the best expected value: the chance that the option is right multiplied by the net value (benefits minus costs) of the outcomes.

For the theory that global warming is caused by human activity, the cost of being wrong is so great, that we should be convinced by only suggestive evidence that it is correct.

But as the climate change debate illustrates, people (including skeptics) employ emotion as well as reason when making a decision or changing their mind. We have inbuilt biases in our psychology that sometimes make us too strongly resist changing our mind (false negative mistake); and other biases that sometimes make us change our minds too easily and we get it wrong the other way (false positive mistake).

So a skeptic who really wants to make the best bets should not only critically appraise the evidence for risks of bias or error and the reasoning for flaws, but should also take active steps to debias their own decision-making using the insights that cognitive science gives us. This article suggests how we might do this:

Metacognitive experiences and the intricacies of setting people straight: implications for debiasing and public information campaigns

The energy industry spends hundreds of millions of dollars on lobbying the US government against recognition of anthropogenic global warming. This money goes overwhelmingly to lobbyists, PR firms, lawyers and emeritus professors in subjects that the public might mistake for something to do with climate science.

For much less than this, they could pay pensions to a few established climate scientists, who, I am sure, would be feeling a bit of cognitive dissonance and guilt about their part in the hoax. Or, for much the same sum as they currently spend, they could finance their own ('disinterested') research in climate science.

The fact that they don't (they must surely have tried the first) seems to me to be clear evidence against the conspiracy theory, even though it is not evidence for AGW.

Yogzotot"Re-reading Randi's comments, I strongly suspect this first post is a decoy. Exactly because he uses the same rhetorics as you would find with usual arguments defending quackery or other 'denialisms'."

Le Canard Noir"Yogzotot – I think that is a very real possibility."

I hate to say this but, unfortunately, this is a genuine Randi article.

If you don't think so, you might care to read the absolute howlers he made regarding evolution earlier this year. Despite this being pointed out to him, Randi has never retracted them. There have been other many examples as well, though I don't have time to detail them here.

I suppose some latitude has to be given because of his age, but it is sad to see him descend to the ranks of the quacks he was so successful at debunking in the past.

@Ben: my best offer to your challenge has to come with a caveat. I believe that the widely held belief that eating meat containing cholesterol leads to heart disease is wrong despite the seeming concensus on the subject. Though this falsehood is NOT being upheld by virtue of a conspiracy. Conspiracy by my definition means a willful, concerted effort of several people, but I don't think that's why the diet-heart/cholesterol has survived for so long despite being wrong.

Eventually that mistake will be corrected by science – which will progress better when the old guard of fat hysterics slowly die off.

I really try to keep out of the climate debate, because I get an icky feeling when I delve into it. I really, really like the idea of saving the planet and making it a paradise for us, but why – WHY – do everyone act like raving mad religionists trying to dumb down the question to one and only one factor: CO2. My soft, imprecise brain pretty much yells at me that this is no different than treating all heart disease as caused by saturated fat. As if there were no dynamics involved and we can just go linear on everyone.

It rubs me the wrong way so hard that I'm getting ready to fall down the likely wrong side of the fence out of nothing but spite.

Politicians – holding the lowest public respect rankings – instantly contaminate a point of view when they are seen en masse to support it. The public can find it difficult to openly support various Peruvian-hat-wearing howling gangs of 'green' issue militants screaming for global caring. The public cannot be a united group able to form a consensus one way or the other and when badly hit and shocked by our current economic recession etc. brought on by politicians – no doubt advised by financial experts, some may even have had PhDs – we are naturally wary of political positions which appear likely to clobber us with even more taxation and social restriction. The mainstream media aren't exactly slow with red-top headlines spewing 'scientific' claims and counter-claims which only serve to destablise proper scientific method and implications in their readers minds. Perhaps the scientific 'consensus' and the mixed bag of scientific and lay sceptics would have an easier task to demonstrate the truth of the matter if not entangled with politicians about whom few, in the global electorate, are not wholly sceptical. The public is therefore faced with four main influential groups (politicians, scientists, media, green pressure groups) all of whom can initiate the auromatic reflex of public scepticism. Throw in 'big business' and the various politico-financial elites and it's little wonder us punters are hacked off!

This situation reminds me of several other recent discussions about the bona fides of various skeptics. The most famous of these is Bill Maher of course. But criticism of Michael Shermer vis-a-vis his espousal of libertarianism have also raised accusations that he is not following skeptical principles in that area. I was also involved in a recent discussion of whether or not film critic Roger Ebert qualifies for the label "skeptic".

The conclusion I am arriving at is that it is not possible anymore to treat "skeptic" as a black-or-white label that can be universally applied to a person. You have to consider topic area. Nobody, not even Randi, is a "skeptic-at-large" anymore. People are only skeptics in specific areas they have taken great time to study.

The reason for this is simple, I think. Skepticism is based in science. And since the beginning of the modern skepticism movement in the 1970s, the volume of information being produced by science as a whole has grown by several orders of magnitude. It is unreasonable to assume that a normal person can keep up with every possible detail of all the scientific areas that skepticism covers.

I've seen people make extreme remarks based on Randi's article such as "he's pissing his reputation down the toilet". I think these are unwarranted. I dearly love Randi, but I've always seen him as a subject matter expert in specific areas. Those include paranormal claims such as clairvoyance, telekinesis, dowsing and so on. He also has a good grounding in alternative medicine issues. And of course because he's a gadget nerd himself, he's a good source on home stereo and other technology scams.

But beyond that? I think it is unreasonable in this day and age for someone to expect even a full-time skeptic like Randi to keep completely up to speed on every single skeptical topic. And climate change is a huge topic to keep up with.

Science can be wrong sometimes. It self-corrects. So it is with skeptics. They're wrong sometimes. The good ones self-correct eventually. I see no reason to doubt that Randi will do so.

It's interesting to note that in Michael Shermer's open letter to Bill Maher on vaccinations it appears that Shermer initially was a global warming skeptic. He changed his mind later. ( See http://richarddawkins.net/articles/4465 )

As I said earlier something about the whole climate debate is rubbing me the wrong way – or biasing me from the outset against it.

I think it's a form & content issue and how those two usually play out. Usually when someone argues for a hypothesis in a certain way we can almost always predict that the content of the message is wrong too. Nutty conspiracy theories and hoaxes and urban legends tend to "smell" a certain way, and when suddenly global climate change borrows its form from highly politicized and even religious ways of arguing, well … it doesn't exactly confirm that global warming (or whatever) is wrong, but their argument surely has a bad start.

i think most peeople in medicine have been pretty iffy about the "eating cholesterol causes heart disease" thing for ages tho, as soon as contradictory evidenc started percolating through, and ppl wld now say (i think correctly) that there's something in there that involves cholesterol but its not clear what or how, or that specifically eating less cholesterol is better, but statins work a bit, and they lower cholesterol, and the blood levels correlate with some stuff, etc. it doesnt feel to me like cholesterol and heart disease is a case of almost everyone ignoring the currently available evidence against a theory. possibly a bit more organisational inertia among doctors than working epidemiologists and cardiology researchers too (big field, lots of new info all the time, and we're a bit slow in the head anyway).

Yes, indeed. I see two main aspects of this that make it troublesome for skeptics.

One is oversimplification. We often label people using such terms as "denier" or "skeptic". But your opinions on AGW can vary in several orthogonal directions, so its much more complex than that. There are at least 5 (possibly more) aspects of AGW:

1. Is the Earth warming?2. Are humans the primary cause?3. Do we have the technical capacity to stop it?4. Is stopping it possible without collapsing our society as we know it?5. Should we even try, or should we just adapt to the change?

Questions 1 and 2 are the only areas where "denier" can really be thrown around. Question 3 is still open to debate in my opinion, as I've seen good information on both sides. Questions 4 and 5 have a huge socio-political component and thus may not even be good questions for skeptics.

The other aspect of this is politicization. Since questions 4 and 5 have political components, debating them turns into a political discussion instead of a scientific one. This is another area where skeptics often run aground, because we tend to be distributed across different parts of the political spectrum.

@BenGoldacre:"can anyone think of a case where the vast overwhelming majority of scientists … held an opinion that was demonstrably wrong with reference to the facts available the time?"

I know its not a perfect fit, but what about the "stomach ulcers are caused by acid/stress" thing? I'm thinking about the period after Robin Warren and Barry Marshall put forth their h.pylori theory but before it was generally accepted. They had data, but didn't people refuse to accept it for a while?

It is interesting to see how the 'sceptics' have treated 'scepticism'. Some sceptics have already called Randi a "denier".

The way in which people get lumped in to the category "denier" or "good scientist" owes very little to the argument they make. Randi neither says that "there's no such thing as global warming", nor that "nothing should be done about it". It seems that the designation of these categories is political, rather than scientific.

I would argue that the 'consensus' position (which we putatively test any argument against to determine which category any person or argument belongs to) is nebulous. The phenomenon of 'denial' therefore is assumed to exist without a proper conception of the object of the 'consensus', such that we can say what it is 'denial' is supposed to contradict. There is no single object of consensus, and there is therefore no single object of denial. Moreover, there is no measure of the strength of the consensus, i.e. how many scientists it really represents.

The IPCC is often held to represent the consensus. But an inspection of the assessment reports reveals it to be a huge document, written by teams of people working independently of each other, with a range of scientific and non-scientific specialisms, to produce assessments of the existing research in a wide range of fields, to varying degrees of certainty.

Isn't a 'denier' of the work of WGII therefore a very different 'denier' to the 'denier' who denies some or all of the work of WGI? And isn't the climate change sceptic who thinks that 'climate change is real', but thinks the infamous effort to reconstruct historical temperatures is inadequate to make a political argument for action a very different 'denier' to the 'denier' who thinks the argument for mitigation over adaptation is ill-conceived?

The 'consensus' is not a single point of convergence for the 'vast majority of climate scientists'. Over-emphasising the phenomenon of denial as though it were carries the consequence of making denial a very plausible argument, because what it demonstrates is the way in which the 'debate' is political well before it is 'scientific', and exists on insecure premises.

@BenGoldacre:"can anyone think of a case where the vast overwhelming majority of scientists … held an opinion that was demonstrably wrong with reference to the facts available the time?"

But can anyone think of a case where a scientific argument has been the basis for such a comprehensive transformation of the world's entire political, economic, industrial and social organisation?

The process by which we move from "CO2 from human industry has caused changes to the atmosphere, causing it to warm", to "if we don't change the way we live right now, we're all going to die" needs more scrutiny. While it goes without it, and while many people act as though the imperative was issued by science itself, there will be a question mark over the legitimacy of political responses to climate change, and an even greater question mark over the relationship between scientific and political authority.

One of many problems is the conflation of the climate science (general consensus within the science community) with the economic responses being suggested (is there a similarly unified view amongst economists that there is only one 'solution'? I don't know – but I suspect not). It seems to me (perhaps because I don't get out enough) that much of the antipathy to MMCC science is voiced by the libertarian right. There is no reason in prinicple why one part of the political specturm should be more critical of the science than any other, but it is likely that the right will be more anatagonistic to the co-operative, possibly self-damaging strategies that seem to be the main economic policy options. And it must be said that some of the mega cap and trade schemes are vulnerable to organised crime and corruption which will alienate many who are in any case suspicious of big-goverment/nanny state/ – choose your slur.

If the preferred policies in response to MMCC were portrayed as money-making, 'freedom' giving, adventurous and individualistic I'd bet that hostility to the science would change. The truth is that such policies are available: individual micro-power generation, business exploiting green-technology, maybe even bold geo-engineering schemes are likely to be part of the mix over the next 20 years.

This is a really excellent post on a very important topic. I feel global warming is the single-most pressing issue we'll ever face, but as you've pointed out it also highlights the danger of 'extreme scepticism'. If it is truly the case, I'm saddened by James Randi's stance; as a courageous and entertaining battler of pseudo-science and nonsense, his views will sway others.

Ben – one example that I've heard raised before is freudianism/psychodynamic psychotherapy. Now I don't personally think it fits the bill, as despite being a broad consensus 'theme' of ideas for a number of decades it didn't have the status of a scientifically held theory as opposed to un-testable assertions. However I can see that it could seem to some as a dominant 'scientific' consensus, now overturned.

"can anyone think of a case where the vast overwhelming majority of scientists, in their own field, all around the world, for a long period of time, by virtue of conspiracy (since that is the commonest accusation) or foolishness, held an opinion that was demonstrably wrong with reference to the facts available the time? and unanimously refused to concede to good quality arguments against their position? i'd be interested if there were any"

plus as you later say, having to be 20th Century+. I'd suggest you give up looking. You're not exactly being flexible. Why not add "and which were exposed by hackers." to really finish off the quest.

I mean "all around the world" – that's a pretty bizarre constraint in itself.

The conspiracy as such is in the behaviour at CRU and is not necessarily even fully conscious – is it a lie if you believe it to be true? The reality is, as will come to be understood by more of the lamely compliant 'skeptics' so shocked by Randi's statement, that most of climate science is completely malleable to interpretation/ adjustment and relies almost entirely on rhetoric (unprecedented, pre-industrial, natural v anthropogenic, pollutant etc) to persuade the feeble-minded. And for you less feeble 'skeptics' try reading about "distance lending enchantment" and Fleick's work et seq.

I wouldn't say that Freudian/psychological theories were overwhelmingly accepted. After all, it was these (along with Marxism) that drove Popper to come up with falsification to prevent them from being regarded as scientific.

@Tim Farley: "Yes, indeed. I see two main aspects of this that make it troublesome for skeptics. One is oversimplification …"

Yes, indeed. There's honeste also a bunch of things that I'd love to hear more about on this topic. I alway wondered what the main dynamic players were other than just the CO2. For example I could easily imagine clouds having an effect. Say the cloud coverage got thicker, wouldn't that lower temperature yet at the same time make everything inside the "cloud shell" get more temperature stable, or …? Maybe it's a stupid question that can be brushed away easily by someone who knows the stuff, I'm just sosurprised no one ever picked it up and talked about it. Just so everyone could get smarter.

There's also another special thing about the climate isuse that sets it apart from many other political issues. Normally what we'd see are politicians dragging their dinosaur clay feet way behind the latest scientific discoveries. Yet, from the outset the ominous predictions were caught almost immediately by politicians who either believe strongly in the issue or who could see political advantage to adopting the mantle of "World Savior".

That dragging of feet – while sometimes frustrating – at least means that sciene has usually reached a very decent level of certainty at the time it gets dumbed down for sale to the public.

This isn't science – more social assumption. How about Irish prisoners during anti-Irish racist periods – Birmingham 6, Guildford 4, Martina Shanahan (Winchester 3), Judy Ward, Danny McNamee etc. That used evidence. A consensus approved it (jury) and it took years to challenge. Socially we are capable of this. We are still doing it. Ask Jack of Kent.

I was interested once and did a bit of research and at least 1/2 of all Irish women on extreme sentencea in England (more than 15 years) were aquitted at various appeals. This was made up to 2/3 by those who upheld their innocence and behaved as thus after release ie no contact with any policits eg Gillespie sisters. What if that were true for the men too? What social assumptions would that challenge? How would we feel about our justice system during that period if we thought that might be true. (I'll send you the names and sentences and stories if you want).

Every one of them was sent down on consensus by evidence. Social assumptions are very powerful.

Not to undermine you. I'm someone who feels that we've taken taken more out of this planet in the last 200 years than was ever taken before and we are doing so expontially. I am tired of the terror-mongers. Just tell us what are the best things we can do to help ourselves. Stop terrifying us. I think a lot of the denying is because pwople can't cope with the fear anymore.

I don't think that is a fair comparison Wen as juries operate on principles that are the opposite to modern science. They do not scrupulously record minutiae, they do not have to record their thinking and have it examined and challenged. They operate on instinct, emotion and feeling not on calculation of probabilities and careful study.

It is no good blaming the messengers for people's refusal to be rational or reasonable, that is a childish cop-out. Humans have a remarkable capability for self-deception which is probably an essential tool of social living but blaming others for your own self-deceptions is just silly.

This is a very interesting posting for me, as I am, as mentioned elsewhere on the site, becoming very curious – and very concerned – by the anti-science feelings that seem to be emerging in regard to climate change.

The question that I would ask in regard to this particular section of discussion is why Mr Randi's views on science seem to be so important. Surely in terms of the fundamental science, the views of the world's climatologists are what matter? And in terms of action, the views of the world's politicians?

As I write, the news has been coming in of what appears to be a limited level of agreement at Copenhagen, which initially seems to be not enough to stop a global temperature rise of at least two degrees and on some analyses three degrees. The implications of this level of rise are disturbing, so I would have thought that this would be the aspect of the climate change issue that would be more likely to be in the front line tonight.

Forgive my asking this question if it seems a bit naive, but I really don't understand the reasoning here, and would like to be better informed.

As to why Randi's views are thought important – certainly I, and I think many others, have great respect for his efforts in combatting sloppy thinking and design of supposed proofs of pseudo-scientific phenomena (or in other words, self-deluding apologists for alt-medicine, alien contacts, etc). As Mark Bailey says, Randi's later post clarifies his take on climate change, and sort of apologises for unintentional support of the climate deniers.

SourceWatch has an informative piece on the Petition Project (that Randi could have usefully read earlier!!)

Actually both Randi and all of you write here nonsense and blabbing.And the truth is that the global warming is a thing, which requires additional scientific investigations.But despite of it, the scoundrels, ruling USA and other top industrialized countries, try to use unsufficiently studied fact of global warming to get dominance in the world and to turn other countries into their economical and political slaves.

And all of you with your false harangues are simply political prostitutes.

Usually these posts are well thought through, amusing and with a point to make but this one has none of these attributes and flounders a bit, not really knowing what it is for.

Remember, the scientific community, at one time, held the earth to be flat and the application of leeches was once a popular 'cure' for all sorts of ailments. Just because lots of people agree about something doesn't automatically mean they are right.

Climatologists know more than me or you about these issues but still probably know less than a gnat's whisker about all there is to be known, so on an absolute scale their lack of understanding isn't too far away from everyone elses, but they do not portray it thus.

I take the view that a move to a carbon free economy is a sensible direction to go in anyway, simply because one day it is going to run out.

Dear AllThe problem with 'knowledge', whether scientific or instinctive is that it is a 'ledge of knowing', not a plateau nor a valley floor nor the summit- just a ledge. To understand we are only able to stand under the greater mountain of wisdom as it is far too voluminous to be held in the grasp of an intellect. Hence we lack the words: 'overstand';'undersit' and we scrabble around/ on/ under the ledge we happen to choose to observe or happen to have had placed within our view. There will be other ledges around the one in our sight and the other side of the mountain will have ledges too. "Don't diss my knowledge", I might say- whilst the mountain will probably chortle at my naivety and the winds and snow will follow the rain and flowers as sun follows moon in her lunar dance.

From my reading of the Randi article his fundamental understanding of what the cause global warming is is wrong. He stated that it is supposedly caused by burning fossil and non fossil fuels giving off heat, causing warming. There was no mention of greenhouse gasses or the greenhouse effect, therfore he is being skeptical about a false version of "man made" global warming right from the start.

While of course we cannot be experts in every field, on important issues such as global climate change we can try to inform ourselves as best we can. Randi's biggest problem is that he seems to lack even the most basic understanding of what the science is all about. In his follow up post, he clearly stated that he believes the argument is that anthropogenic global warming is caused by waste heat from burning fossil fuel and wood products. He seems never even to have heard of greenhouse gases or grasped the fundamental argument. I'm not a climate scientist but I have been perfectly capable of getting a handle on the basic physics involved. A decent level of understanding, even if you lack true expertise, can go a long way toward evaluating whether scientific claims have merit.

the scientific community, at one time, held the earth to be flat. Not so! As soon as people started to investigate this question systematically, they figured out the truth. The ancient Greeks knew that the earth was a sphere and even made a very accurate measurement of its diameter. The belief in leeches was not held by "the scientific community," it pre-dates the application of science to medicine.

So if the ancient Egyptians, Paracelsus and Hippocrates were aware of and able to use Homeopathic principles alongside Allopathic principles for the benefit of their patients, in theory, so should we, unless we are all called Galen and insist on Cartesian thinking without exception (depends whether the Dr, with the time lords' assistance, can reverse the actions of the master in the final episode of 'The End of Time')- innit?

Really excellent post. This is a key issue, I think most would agree, for sceptics.

This is partly because it seems that "climate sceptic" is becoming synonymous with "climate denier" in the public eye, which is a great shame as it confuses a rational attitude to evaluating evidence with a deliberate suppression and distortion of that evidence. That's a bad thing for the image of scepticism and for sceptical people everywhere.

I am a climate sceptic, but my scepticism has led me to believe that global warming (very probably) is real and (very probably) is a problem worth tackling.

From memory I cant ever remember a consensus of scientists where dissent was banned and attacked where the consensus was eventually proved correct..

The flat earth consensus was very wide spread among the main stream it was the minority sceptics that were proven right..

Maybe for the first time in recorded history, that the mainstream authoritarian consensus will be correct,

Strangely they have put their reputation on the line over the weather !!!!

Maybe persecuting all dissent or question this time will prove to be the best course of action.

If nothing happens and the temperate just rises like it has since the last Ice age, no more or maybe less will the experts humbly apologies and return the billions

the net decade will possibly destroy the peoples respect for science and its methods, banning all dissent or questioning has a very high price to pay if you are wrong.

Maybe the weather is not something we should be certain about…. we should leave the door open for an embarrassed "Ooop well I thought I was right" We should make room for Randi and his kind, they may just be the only ones left with any creadability left when this panic all die down in ten years or so !!

Please take note of the claims.. every thing seem to be caused by global warming now days – "compensate us NOW"

The cave men were right during the Ice Age, the planet did warm up and it was caused by men…. the women are innocent

in the rush to jump onto a populist bandwagon you have forgotten to listen and rationally evaluate the claims.

NO other area of science makes absolute decorations of TRUTH, just the people who watch the weather ????

Be afraid be very afraid …….

Not even gravity is spoken of in terms of absolute fact, the questioning and testing is continuing, but not so with the weather, this is now uncontested absolute final fact…. the inner scientist in all of you should be disgusted with this consensus.

And you lot pock fun at the blind faith of the snake oil salesman… shame on you shame!!!!

Why are we hung up on the "how can non-experts render a proper opinion?" question? Don't we live in a world where most of us have no clue about just why certain things are true but yet believe they are based on our trust in science? Randi is no different than the majority in his ignorance on climate science. The striking thing here is that he chose not to trust the vast majority of scientists on this issue. Of course nothing is certain, but when laying down bets on something isn't it smartest to go with what scientists have to say about it?

One of the problems here is that Randi acknowledged his ignorance, but went ahead and wrote a blog-post relying on arguments approaching denialism. His arguments were not down-right denialist, but came pretty close due to "the petition project".

If he had said something like: "Based on my limited understanding of the subject, it seems like the scientific consensus on AGW is not properly robust. Therefore I deem it more responsible to focus our political debate around other areas of environmental protection until better research is done." …I don't think as many people would have gotten their knickers in a twist. The first blogpost was not up to the standards we have come to expect from Randi.

Ben’s question was not about theories / hypotheses that were long held although wrong, but such that were held *inspite* of contradicting evidence.

Your list contains, as far as I can tell, only hypotheses that simply couldn’t be put to the test until later times – and when they were finally tested, they were scrapped. Good scientific practice.

Or am I seriously mistaken here?
Daniel

PS: Wave/particle theory of light, though… for many practical applications those are still alive and kicking. Maybe as disciplines of quantum mechanics, but displaying both the qualities of wave and particle.

I think Bertrand Russell’s guide is excellent. But, in my view, the reason that Climate Change produces such polarised opinions in the public and political arena, in spite of coherent and trustworthy information from Climate Change scientists and the IPCC, is that Russell’s ‘ordinary man’ thinks that for a scientific claim to have validity it must go beyond the very probable to the certain. “Prove it!” becomes the cry from the sceptics corner. In most cases, having sufficient evidence will turn a hypothesis into a practical theory or model that is deemed so reliable that it can be regarded as true or ‘proved’. But when working with an interactive open dynamic system (the climate) on a single sample of a type (the earth), there is no possibility of providing the type of statistical proof that, for example, might be forthcoming from a medical blind trial involving 10,000 samples of human being.

Moreover, the idea that science can also predict the likely outcomes from previously established first principles is so often forgotten by the ‘ordinary man’ because so few people are taught the principles (basic chemistry and physics) or how to apply them. Furthermore, journalists (many of whom are scientifically illiterate) are often guilty of describing climate science as ‘new’ or ‘revolutionary’ or ‘untested’ (based on the fact that it is only recently that sufficiently powerful computers have been available to crunch the numbers) whereas the physics and chemistry have been understood for a very long time. Results of initial ‘back of an envelope’ predictions for many modern issues such as peak oil and climate change, using first principles, in the 1970s and 80s, have not proved to be far away from modern sophisticated models and, because our single sample (the earth) is subject to time and exponential economic growth, the sense of urgency coming from environmental scientists was treated as panic by the media – partly because the back of the envelope predictions were so dire and partly because the panic was real.

The tragedy is that the major industrialised countries could have acted on climate change 30 years earlier if our ‘ordinary men’ running governments had the ability to sit for a few weeks with a calculator, a science data book and a sharp pencil.

Having struggled through the Leppard Blog, I have to resort to a simple fact, instead of dreaming and demonstrating wide reading skills.

The measurement that shows the sea level is rising was taken from Hong Kong, which is slowly sinking. Had it been taken from Bergen it would have shown that the sea level is falling, because Scandinavia is still rising after being squashed in the ice age. Anyway, it has become ever colder since 1998, so what is everybody going on about?

I recall attending the British Association for the Advancement of Science meeting in Cambridge in the early 60s. There were two outstanding presentations.

The first demonstrated mathematically and aeronautically that man-powered flight was now and ever impossible, and the person who had offered a prize to the first man-powered flight over the English Channel’s money was safe. Soon afterwards a man pedalled his aircraft across the Channel.

The second explained graphically that pharmaceuticals were the answer to all medical questions, and that schizophrenia, for example, would be cured shortly and for ever by a short course of pills from the chemists. As it is, Pharmacueticals are the biggest killer in the world today, Check it out.